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      <title>@RequestBody和@ResponseBody注解的作用是什么 - 交互式测验</title>
      <style>
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          min-height: 100vh;
          margin: 0;
          padding: 20px;
          box-sizing: border-box;
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        .main-wrapper {
            position: relative;
            width: 100%;
            max-width: 900px; /* Wider to accommodate buttons */
            display: flex;
            justify-content: center;
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          box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
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          max-width: 700px;
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        .quiz-header {
          background-color: #4a90e2;
          color: white;
          padding: 20px 30px;
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        .quiz-header h1 {
          margin: 0;
          font-size: 24px;
          font-weight: 700;
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        .quiz-header p {
            margin: 5px 0 0;
            font-size: 14px;
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        .quiz-body {
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        .progress-bar {
            display: none; /* 隐藏进度条 */
            width: 100%;
            background-color: #e0e0e0;
            border-radius: 5px;
            height: 10px;
            margin-bottom: 20px;
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        #progress-indicator {
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        #question-container {
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        #question-text {
          font-size: 18px;
          font-weight: 500;
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        .options-list {
          list-style: none;
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        .option-item {
          background-color: #f8f9fa;
          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
        }

        .option-item:hover {
          background-color: #e9ecef;
        }
        
        .option-item.selected {
            background-color: #d1e7fd;
            border-color: #4a90e2;
        }

        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
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        #next-btn {
            background-color: #28a745;
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        .nav-btn:hover {
          background-color: #357abd;
          transform: scale(1.05);
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        .nav-btn:disabled {
            background-color: #a0c3e8;
            cursor: not-allowed;
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        #result-container {
            border-top: 1px solid #eee;
        }
        
        .result-box {
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
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        .result-box.correct {
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            color: #155724;
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        .result-box.incorrect {
            background-color: #f8d7da;
            border: 1px solid #f5c6cb;
            color: #721c24;
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        .result-box h3 {
            margin-top: 0;
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        .explanation-text {
            margin-top: 15px;
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        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
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        .final-score-container {
            padding: 40px;
            text-align: center;
        }
        .final-score-container h2 {
            margin-top: 0;
            margin-bottom: 30px;
        }
        .score-summary {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }
        .score-card {
            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            border: 1px solid #e9ecef;
        }
        .score-card h3 {
            margin: 0 0 10px;
            font-size: 16px;
            font-weight: 500;
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        .score-card p {
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            font-size: 28px;
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        .score-details table {
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            font-size: 16px;
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        .score-details td {
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        .score-details td:last-child {
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            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>@RequestBody和@ResponseBody注解的作用是什么 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "在Spring MVC中，`@RequestBody`注解的核心作用是什么？",
    "options": [
      "将Java对象序列化为JSON格式并写入HTTP响应体。",
      "将HTTP请求体（如JSON或XML）自动反序列化并绑定到方法的Java对象参数上。",
      "将URL中的查询参数（Query Parameters）绑定到方法的参数上。",
      "指定控制器方法执行后要渲染的视图名称。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`@RequestBody`注解用于读取HTTP请求的内容（通常是JSON或XML格式），并通过`HttpMessageConverter`将其反序列化成一个Java对象，然后绑定到控制器方法的参数上。这极大地简化了处理POST或PUT请求中复杂数据的过程。",
    "source": "文档中「@RequestBody注解」部分的「1. @RequestBody 的作用与基本用法」",
    "hint": "文档提到，该注解允许我们将前端传递的JSON请求体自动转换为Java对象。"
  },
  {
    "question": "当一个Spring MVC控制器的方法被`@ResponseBody`注解标记时，其返回值会发生什么变化？",
    "options": [
      "返回值被视为一个视图名称，Spring会寻找并渲染对应的模板文件。",
      "返回值被自动存储在HTTP Session中，以供后续请求使用。",
      "返回值（例如一个Java对象）会被消息转换器序列化（如转为JSON），并直接写入HTTP响应体中，而不是去解析视图。",
      "该方法必须返回一个`ModelAndView`对象，否则系统会抛出异常。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "加上`@ResponseBody`后，Spring MVC会跳过常规的视图解析流程。取而代之的是，它会使用一个`HttpMessageConverter`（如`MappingJackson2HttpMessageConverter`）将方法的返回值序列化成特定格式（如JSON），并直接作为HTTP响应的内容返回给客户端。",
    "source": "文档中「@ResponseBody注解」部分的「1. @ResponseBody 的作用与基本用法」",
    "hint": "文档中有一句话：“加上 `@ResponseBody` 后，返回的内容将直接作为 HTTP 响应返回，而不是视图名。”"
  },
  {
    "question": "当Spring MVC处理一个带有`@RequestBody`的请求时，它主要依据什么来选择合适的`HttpMessageConverter`进行数据解析？",
    "options": [
      "HTTP请求头中的`Accept`字段。",
      "控制器方法参数的Java类型名称。",
      "HTTP请求头中的`Content-Type`字段。",
      "服务器上预设的全局默认配置。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "Spring MVC通过检查HTTP请求的`Content-Type`头来确定请求体的媒体类型（例如`application/json`）。然后，它会查找已注册的、能够处理该媒体类型的`HttpMessageConverter`来进行反序列化操作。",
    "source": "文档中「@RequestBody注解」部分的「2. 工作原理」",
    "hint": "思考一下，哪个HTTP头是用来描述发送给服务器的数据格式的？"
  },
  {
    "question": "`@RestController`注解在Spring中扮演了什么角色？",
    "options": [
      "它是一个组合注解，等同于在类上同时使用`@Controller`和`@ResponseBody`。",
      "它是一个专门用于处理GET请求的类级别注解。",
      "它强制该控制器下的所有方法都必须使用`@RequestBody`来接收参数。",
      "它完全取代了`@Controller`，并提供了更高级的依赖注入功能。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "`@RestController`是一个便捷的注解，它结合了`@Controller`和`@ResponseBody`的功能。当一个类被`@RestController`标记时，该类中所有方法的返回值都会被自动处理为HTTP响应体，无需在每个方法上单独添加`@ResponseBody`。",
    "source": "文档中「@ResponseBody注解」部分的「4. @RestController 注解」",
    "hint": "文档描述这个注解“相当于为控制器类的所有方法自动添加了 `@ResponseBody` 注解”。"
  },
  {
    "question": "为了对通过`@RequestBody`绑定的对象（例如一个`UserDTO`）启用JSR 303/380数据验证，应在方法参数前添加哪个注解？",
    "options": [
      "@NotNull",
      "@Autowired",
      "@Valid",
      "@Transactional"
    ],
    "correctAnswerIndex": 2,
    "explanation": "在`@RequestBody`注解的参数前加上`@Valid`注解，会触发Spring对该对象进行数据验证。Spring会检查对象内部使用JSR 303/380注解（如`@NotNull`, `@Size`等）定义的约束规则。如果验证失败，将抛出`MethodArgumentNotValidException`。",
    "source": "文档中「错误处理与验证」部分的「1. 验证机制概述」",
    "hint": "文档中有一个代码示例展示了如何结合 `@RequestBody` 使用一个注解来触发验证。"
  },
  {
    "question": "当使用`@Valid @RequestBody`进行数据验证且验证失败时，Spring MVC默认会抛出哪个特定的异常？",
    "options": [
      "HttpMessageNotReadableException",
      "NullPointerException",
      "MethodArgumentNotValidException",
      "IllegalStateException"
    ],
    "correctAnswerIndex": 2,
    "explanation": "`MethodArgumentNotValidException`是专门用于表示当一个用`@Valid`注解的方法参数验证失败时抛出的异常。开发者可以通过`@ControllerAdvice`和`@ExceptionHandler`来全局捕获此异常，并返回结构化的错误信息给客户端。",
    "source": "文档中「错误处理与验证」部分的「2.1 @ExceptionHandler 和全局异常处理」",
    "hint": "当请求体格式正确但内容不符合业务验证规则时，会抛出一个与“方法参数无效”相关的异常。"
  },
  {
    "question": "在处理一个复杂的请求对象时（例如`Order`对象内部包含一个`Customer`对象），如何确保对嵌套的`Customer`对象也执行数据验证？",
    "options": [
      "只需要在`Customer`类的字段上添加验证注解即可，Spring会自动发现并验证。",
      "在`Order`类中，为`Customer`类型的字段同时添加`@Valid`注解。",
      "在控制器方法的`@RequestBody`参数前添加两个`@Valid`注解。",
      "为`Customer`类本身添加`@Valid`注解。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "为了实现级联验证（即验证嵌套对象），你需要在包含嵌套对象的字段上使用`@Valid`注解。这样，当Spring验证外层对象（如`Order`）时，它会看到`@Valid`标记，并递归地对内部的`Customer`对象也执行验证。",
    "source": "文档中「错误处理与验证」部分的「5. 处理嵌套对象的验证」",
    "hint": "文档中提到，通过在嵌套对象上使用一个特定的注解，Spring 会自动“深入”嵌套对象进行验证。"
  },
  {
    "question": "当一个方法使用`@ResponseBody`返回一个Java对象时，Spring MVC会根据什么信息来决定是将其序列化为JSON还是XML？",
    "options": [
      "服务器的全局配置文件，该文件固定了唯一的响应格式。",
      "客户端请求头中的 `Content-Type` 字段。",
      "返回的Java对象的类名后缀。",
      "客户端请求头中的 `Accept` 字段。"
    ],
    "correctAnswerIndex": 3,
    "explanation": "`Accept` HTTP请求头由客户端发送，用来告知服务器它能够理解和处理的媒体类型。Spring MVC会检查这个头（例如`Accept: application/json`），并选择一个能够生成相应格式的`HttpMessageConverter`来序列化返回值。",
    "source": "文档中「@ResponseBody注解」部分的「5.2 Content-Type 和 Accept 头」",
    "hint": "客户端通过哪个HTTP头来声明它“接受”什么类型的响应数据？"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  